357 brass resizes bullets

[ButterNutZ]

I might have figured out part of my leading problem in gp100. If I push 158 gr bullet anything over 700fps they will lead, if I keep'em at 650 or so they dont lead. Today loading some ammo got an idea to check out diameter of a loaded round to see maybe brass sizes bullets down from .358, sure enough, case measured .3575. If i subtract case wall thickness, that would make bullets way undersized. I'm using lee dies to load the ammo. Btu if I shoot GC bullets, they won’t lead even at max loads. Does GC keeps cases from sizing bullets? Or is there some other factor at play here?
How do you guys keep your brass from sizing down bullets?

[leadman]

Check the expander in your powder thru expander, might be undersized. You are expanding the case mouth before seating the boolit aren't you?
If this checks out maybe your boolits are soft and you need to use a harder alloy or water quench them.
A gas check will help maintain boolit diameter.

[462]

Possible causes:
1. Case not expanded enough.
2. Seating die is swaging the boolit to a smaller diameter.
3. Using the Lee Carbide Factory Crimp Die.

Possible solutions:
1. Lyman's famous expanding "M-die".
2. Enlarge (hone) the die's interior.
3. Stop using the infamous Lee crimp die.

Opinion:
1. Seat and crimp in two seperate operations.
2. No need for hard .357 Magnum/.38 Special boolits. In fact, I've found a 50/50 or 2:1 alloy of wheel weights:lead to work perfectly . . . even to maximum Magnum velocities.

[ButterNutZ]

Out of all the options you mentioned 462, maybe Lee expander/ powder through die not working right? It only bells the case mouth a little. I dont use Lee FCD at all, I'm using lee seating die roll crimp ( very little just to close the bell from expander), and there is no way it can down size the bullet, way too much room inside the die.
Other possibility is that resizer is a bit too tight? What is the diameter of a sized case you get after resizing?
What about Lee's universal expander? I'm using one for 35rem and it works great.
I'll look in to maybe getting Lyman's M die.

Thanks

[44man]

How simple is this? Boolits are too soft to withstand seating. Just what do you expect?
Sure, change dies and expander plugs to give up accuracy. Easy solutions so you lose case tension.
The store bought GC boolits are most likely harder. They expand the brass when you seat.
Can you shoot soft? Of course but what is your requirement for accuracy? 15 yards? Steel plates at 7 yards? Leading only? Alloy has little affect and some very soft lead will not lead the bore but can you hit anything?
I never used Lee dies and use Hornady. The expander is short and small so the boolit has to expand brass and the base is going into brass that has not been expanded. The boolit must be tough enough to open the brass. Soft lead is out.
Do hard boolits lead a bore? No, not in the least and I shoot as long as 2 years without cleaning a gun.
Personally I would change the boolit so when you seat a .358" and pull it, it is still .358". I would not change the brass to make it so.
watch the crimp. If it does not open fully, it will also size the soft boolit.

[ButterNutZ]

44man, the GC bullets I was talking about are the ones I made for 35 rem, water cooled WW 200gr RCBS bullet. I reckon you are right about bullet being too soft.

[williamwaco]

Step 1) Read 462 again.

then,

Step 2) Read 44man again.

Then,

Step 3) goto step 1)





.

[44man]

44man, the GC bullets I was talking about are the once I made for 35 rem, water cooled WW 200gr RCBS bullet. I reckon you are right about bullet being too soft.
Those would be just fine.
Try making the 158 gr boolits resist the brass and come back with results.

[runfiverun]

all this expanding is going to cause more issues than they will ever fix.
if the inside of your case is truly the 3575 you only have .0005 neck tension now.
if the boolits are being squeezed by the .0005 then either make them slightly larger to compensate for the squeeze or a bit harder to stop it from occuring.

i wonder often if "cases" [no pun intended] like this aren't where the "make them lots bigger"
thing comes from.

[dragonrider]

"check out diameter of a loaded round to see maybe brass sizes bullets down from .358, sure enough, case measured .3575. " I think you misread your micrometer. I suggest that you should be reading .3775"

If as you posted it is .3575" then your boolit is indeed small by about .020" and you have a bigger problem that just leading.

[ButterNutZ]

Yeap its .3775 and case is about 0.01. typo sorry

[Frank]

ButterNuts:

Yeap its .3775 and case is about 0.01. typo sorry
Measure your case thicknesses exactly. If they are .010, then your bullet is now .3575.
Not bad. If your cases are .012" thick, then your bullet is now .3535.

[btroj]

How big did the bullets start out? If they were .358 to start and got squeezed down to .3575 then why not start with a bigger bullet? Try a .359 or .360 bullet and see if that doesn't help.
Is this really an example of a case sizing the bullet or is it a case of using an undersized bullet in the first place?

[ButterNutZ]

Frank they measure anywhere from 0.011 to 0.0095 on 20 cases that I measured. btroj bullets are .358 from the get go.
If I go with bigger bullet wouldn't case size them uneven? They are not very consistent in thickness, and might size one side more than the other.

[btroj]

I bet a bigger bullet from the start would fix the problem. As for uneven squeezing from uneven brass thickness, we can't do much about it so I don't worry about it. For handgun ammo it just isn't an issue.

Have you slugged the throats or barrel in the revolver? They may also,be bigger than .358.

What size do our bullets drop from the mould? Measure one, seat in a case, pull, and remeasure. It won't have shrunk very much just from neck tension. Yes, this can be an issue in cases like a 9mm but they have a short case with a strong taper from mouth to head. I just don't see "case neck sizing" as a big issue in a 357.

Tink of it this way. A .358 bullet is sized down to .3575. Even if a .360 bullet sized down .002 it is .358 which is bigger than you have now. Your .360 bullet isn't going to lose .002 either.

Bigger bullets are often the answer in leading. I learned that the hard way when I shot a box of commercial .358 bullets that were pretty hard thru my GP100. After 30 rounds it was leaded so bad the bullets hit the target sideways. Those bullets actually only measured. 356! Proved to me right then and there that hard isn't the answer as much as big is.

[Frank]

ButternutZ:

Frank they measure anywhere from 0.011 to 0.0095 on 20 cases that I measured. btroj bullets are .358 from the get go.
If I go with bigger bullet wouldn't case size them uneven? They are not very consistent in thickness, and might size one side more than the other.
If your bullet is .358 and in the brass it seems to be .3575 as measured, then the boolit may be too soft. Use a hammer puller and measure it. If it is hard, it won't size down. A hard bullet will grip the rifling with minimal or no skid. But you also need to slug the barrel. You need to be slightly above groove diameter. If throats are too small they have to be opened up so no sizing takes place there.

[ButterNutZ]

Well I gave up on 158 gr bullets. Lee 125 gr RN loaded with 5gr of unique gave great accuracy at 20 yards and no leading. Need to chrono them to see how fast they are. I might take it up a notch. This load is an absolute pleasure to shoot as well.
Bullet still gets sized down a little, but no leading. I might run this set up next year for our local steel challenge shoot.